1. Field of the Invention
The present invention relates to a method for preparation of plant extract powder and oral compositions containing plant extract powder prepared by the same.
2. Description of the Related Arts
To keep teeth healthy and normal is directly related to the maintenance of body's health as well as that of mouth. After having been grown to a certain age, teeth are not be reconstructed nor regenerated and they are exposed to various agents or unclean oral environments which could cause serious dental diseases.
It is generally known that tooth decay and periodontal diseases, which occupy most of oral diseases, are caused by plaque which is generated by oral microbe colony at the teeth's surface. When saliva forms a sticky thin film covering the teeth's surface, the microbes can form colony there. That is to say, tooth decay is caused by corrosion of enamel which occurs when Hydroxyapatite, a main ingredient of teeth, is dissolved by organic acid produced when anaerobic bacteria in plaque metabolize the saccharides. And periodontal diseases are caused by the accompanying accumulation of plaque which overwhelms the host's protection ability. Therefore, to alleviate the periodontal diseases, the activity of causative bacteria of periodontal diseases has to be suppressed and hematocele of gum having inflammation has to be improved and the gum inflammation has to be alleviated.
To prevent tooth decay and periodontal diseases, it has been used fluoride compounds to prevent the corrosion of enamel and antibiotics such as penicillin, erythromycin, tetracycline or antibacterial agents such as chlorhexidine to die out tooth decaying bacteria. But the excess use of fluorine causes the hardening of cartilage and stomachache and the use of bactericides or antibacterial agents cause various side-effects in the mouth.
Therefore, instead of using artificial antibiotics and bactericides, it has been proposed to use medicinal plant extracts which have an effect on causative bacteria of tooth decay and periodontal diseases. Representative examples include Sanguinaria extract(U.S. Pat. No. 4,689,216), Myrrh, Rhatany, Sage, Chamomile and Echinaecia extract(S. de Rysky; Journal of Clinical Dentistry Vol. I. Supplement A. A22-24, 1988), Sage and Rosemary extract (Japanese Patent Publication Sho 58-134,013), or Hop extract(Japanese Patent Publication Sho 62-138,420). But, these various plant extracts are not stable in the formulation products so that the phase separation of composition is easily occurred.
Therefore, several attempts have been made to stabilize the active principles in the oral compositions. For example, the use of gel capsule to stabilize the oil-soluble ingredient is disclosed in the Japanese Patent Publication Hei 9-110663 as a method for stabilizing the effective ingredients in the oral composition. This gel capsule was prepared through dipping or absorbing the oil-soluble ingredient in inorganic or organic powder carrier and coating it with water-soluble high molecular substance's gel film. But there still exists the problem of instability of composition because the water-soluble coating could be melted when it is injected into the liquid phase oral compositions such as toothpaste during production process or storage.